


An Account of the Nanite Epidemic in Broad Street

by whetherwoman



Category: 1850s London Cholera Epidemic RPF
Genre: Cholera, Gen, IN SPACE!, Robots, epidemiology, robot cholera, robot cholera in space, science montage, so many euphemisms for poop
Language: English
Status: Completed
Published: 2018-12-18
Updated: 2018-12-18
Packaged: 2019-09-21 20:39:08
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,942
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17050184
Author URL: https://archiveofourown.org/users/whetherwoman/pseuds/whetherwoman
Summary: Being an account of Great Danger, Scientific Genius, and the Unlikely Partnership of Human and Android in finding the Deadly Source of a Mysterious Epidemic!





	An Account of the Nanite Epidemic in Broad Street

**Author's Note:**

  * For [seekingferret](https://archiveofourown.org/users/seekingferret/gifts).



### September 1st

On the morning of September 1st, Henry Whitehead peered out his window and was pleased to see it would be a beautiful day. The roiling fog of phosphorus and sulfur was a pleasant warm brown, not the harsh red that had dominated most of the summer, and the slight tinges of yellow indicated a low level of ammonium hydrosulfide. The rover air cleansing systems would be able to run at a smooth 70% efficiency, allowing Henry to visit at least five or six of the nearby Streets on a single charge-up. Of course, decontamination procedures while leaving and entering each Street would take an onerous amount of time, but perhaps it would be worth the difficulty. 

As he dressed, Henry considered which visits he might prioritize - Susan’s baby had been born barely a week prior and she would certainly appreciate a friendly face, and perhaps some arms to hold the child. Tom’s recovery from routine limb replacement had been slower than expected. Knowing Tom, he would be appallingly bored - while he had more options than a human in a similar situation due to his larger data storage capabilities, his processing time negated most of the benefit. Henry made a note to pull the latest 4D holonovela to bring with him - there’d been rumors that the latest advances in visual algorithms were especially designed to engage android visual processors. One of the few perks of Henry’s role as the district psychologist was access to more rapid download speeds than most of his neighbors enjoyed. Although it was likely intended as an incentive to keep up with the latest research, Henry found it more useful for holonovela viewing. After all, his position was not to perform a therapeutic role, but only to maintain connections between his human and android neighbors - and Henry had found very little as useful as a holonovela to bring people together.

Less than an hour later, he arrived at Broad Street, parked the rover in his usual spot in the habitat bay, and waited for the poisonous gasses that had wafted in with him to finish venting. He frowned as he looked around - the bay was unusually empty for such a pleasant day. He had half expected that so many others would take advantage of the weather to go visiting that some out-of-districter would take the spot the locals always left for him, and he would be required to hover-park his rover, at sad cost to its battery life. Yet not only had his usual spot been left open for him, but he could have had his pick of half a dozen others.

His concern only grew as he entered entered the decontamination portal. Charles Mason waited for him on the other side of the clear barrier, and his face was a model of fear and urgency. Henry forced himself not to rush through the decontamination procedures, and in due time emerged.

Charles clasped his hand and shook it firmly. “Henry, just the man we were hoping for. I must ask you to visit the Bates family at once. They… well, you’ll see.”

***

The Bates family turned out to be only the first of the horrifying visits Henry was asked to make that day. It was the smell that assaulted his senses first, of course. The scene could hardly be described - four of the five children already bedridden, the most noxious fluids being expelled in horrific quantities. He provided what comfort he could to their worried parents, until he was called away by another household in equally dire straits. As he left each household, another worried face would appear before him and beg his immediate attendance. Although his expertise as a psychologist could do little for physical needs, most of the people in the cluster of streets around Golden Square had found themselves in the habit of calling upon him in times of need. Henry reminded himself firmly that the care he provided for the mind and heart was as important as caring for the body - more, perhaps, since the nanites each human carried within them did a fine job evolving to protect against the most insidious diseases. At least, he thought with a pang, that had been the case historically. Could this epidemic, for an epidemic it clearly was, mark the beginning of a return to the horrific diseases of ancient times? Already he had heard mutterings of the word “cholera” - but of course, it could not be. He acknowledged the symptoms bore an astonishing resemblance to historical reports of the ancient illness, but even if this was a sign of some previously unknown flaw in the nanite system, the drinking fluids of the Streets were treated and tested beyond any possibility of the disgusting and primitive causes of cholera.

The inhabitants of the district asked for Henry’s presence not because of his job title, but because they knew him. He saw almost all of them weekly, some daily - their joys were his joys, and they knew their sorrows would be his sorrows as well. He set his lips against the thought - what made him most needed during this time of trouble was exactly that which made it difficult for him to do his part. He must put aside the emotions that prevented him from doing what was needed, he told himself, and stepped forward briskly to meet Charles, who was again waiting for him at the decontamination portal doors.

“Charles,” Henry greeted him. “Not another taking, I hope?”

Charles shook his head, his face grim. “Not that I know of. But it’s enough, isn’t it? Over fifty ill, whole families bedridden. It’s shocking, to say the least.”

Henry reached out to Charles and gripped his shoulder comfortingly. “To say the least! I can’t say that I understand it, myself. I shall be in contact with the Board of Public Health immediately upon my return to Berwick Street, you may be sure of that.”

Charles rolled his eyes. “If I may speak freely, Henry, the comfort you brought today is worth twice anything those old windbags may do. It’s always the same with them - known dangers in Stage II of terraforming a planet, adhere to procedures, and never any real help. You watch, if they do visit in person they’ll never leave the decontamination bay.”

“As that might be,” Henry said with a quelling look, “the Board will certainly take action on this event, you have my word.” Charles nodded, clearly only partly reassured. As much as Henry might agree with him privately, he did feel quite sure this epidemic would stir even the most conservative on the Board to action. “At least the scope is somewhat limited,” he said, hoping to reassure. “As shocking as it is to have so many humans stricken by the same cause, our terraforming mission will not be at risk. After all, as we’ve always been told, it is the primary benefit of a mixed human and robot company - there is no danger that can injure both!”

Before Charles could reply, the both heard at the same time rapid footsteps coming down the hall, and turned in anticipation to see young Daisy racing towards them. The young girl’s face held the same expression Henry had seen on so many faces today, and he held himself braced for the news of the latest sufferer. 

“Sir,” panted Daisy, skidding to a stop in front of them. “Sir, come quick, he’s asking for you. It’s Tom, sir, he’s got the cholera!”

Charles and Henry looked at each other, and Henry saw the same ashen horror in his friend’s face he knew must be reflected on his own. Without a word, they ran together down the hall towards poor Tom.

***

### September 2nd

Henry leaned his head wearily on his hand, only half paying attention to the hastily convened meeting of the Board of Public Health currently displayed on his holocom. He had liked to think his experience with the tragedies of life, biologic and synthetic, was both varied and comprehensive. But the past 48 hours had tried him to the depths of his soul, or would if he believed he had one. Tom was only the first android to succumb - now the prostrated included close to equal numbers of humans and androids. The symptoms were almost identical in both, primarily vast fluid loss carrying any waste products the body produced, only varying in that while humans lost water, androids lost the various hydrogen-based liquid compounds that similarly allowed the continuing functioning of their internal systems. The effects were as devastating for both, requiring mechanical rehydration through such barbarous historical methods as intravenous drips. 

Henry had been called upon more or less constantly, at all hours of day and night. Most of his time had been spend in Broad Street, where more than a quarter of all the inhabitants had already fallen ill. But even in his own Berwick Street he was kept on the run. This public hearing was the longest length of time he had been still since his first arrival at Broad Street the previous day. And according to the testimonies he had heard so far, most of the Streets around Golden Square had seen the same devastation - Marshall, Wardour, Pulteney, all the same reports of humans and androids alike stricken by the same devastation.

“... and therefore we must adhere to procedure,” said Mr. Egerton, seemingly drawing to a close. “The dangers of terraforming a planet are both many and known, and we must accept that these tragic events may occasionally strike our community, even as we grieve their necessity.” 

Henry sighed. Poor Charles, right as always. 

“Thank you, Mr. Egerton,” said Dr. Benjamin Hall, the head of the Board, sounding almost as weary as Henry felt. “Next, Dr. John Snow will present his findings on the mode of transmission for the epidemic.”

Henry sighed and closed his eyes, just for a second. They were so heavy. Dr. Snow’s voice wasn’t helping either, soft and almost monotone. He found himself losing focus, catching only pieces of the doctor’s sentences.

“... careful analysis of the expulsions show unexpectedly high volumes of fragmented nanites… statistically significant preponderance of a particular fragment shape, which as you can see here… fluid loss is only due to the natural need to flush out this unusually large volume of nanite death...”

Then Henry’s eyes snapped open and he sat bolt upright. It took him a second to realize what had shocked him out of his stupor, and then he heard what Dr. Snow was saying.

“... is the only explanation that satisfies the particulars of the case. It cannot be atmospheric to the planet, as it has struck only specific locales; it is propagated from neither biologic nor programmatic sources, as it has struck carbon and silicon life without discrimination; in fact, gentle humans and androids, my sincere belief is that the contagion is fluidborne.”

There was a growing murmur from the attendees, and Dr. Snow had to raise his voice to be heard. “Moreover, the facts at hand lead me to believe that the source is the Broad Street waste recycling system.”

At that the murmurs grew to shouts, until Dr. Hall had to raise his voice several decibels to quiet the room. “Enough! Members of the Board and guests, I will have your attention. Dr. Snow, thank you for your testimony, absurd though it is. I can assure you we will investigate your hypothesis with all due attention. We’ve all had several long days and, I’m sure, there are more to come; thank you all for your time and we will reconvene when we all have more reliable data to share.” The transmission stopped abruptly.

Henry sat for a long moment, stunned and appalled by what he had heard. It was irresponsible verging on dangerous to promote such an obviously incorrect theory. Dead nanites were, by their nature, harmless; that was why nanites were built to fragment upon exiting the body. It was impossible that live nanites could enter the water system, let alone remain throughout the comprehensive waste recycling process. Cleansing even fragments of nanites was the first step in any recycling system; even though they were harmless in themselves, they hindered the separation of organic and inorganic materials later in the process. Terraforming projects prioritized state-of-the-art waste recycling technology, and any malfunction would have been discovered long before the slightest chance of harm reached individuals. Henry had full confidence in the fluids of their waste recycling systems - he himself had encouraged sufferers to imbibe as much as possible to encourage their rehydration. When fluid was what the ill needed most, how could this Dr. Snow countenance trying to discourage its use? 

He couldn’t get the man’s long, stern face out of his mind as he prepared himself for bed. He lay in the dark, still seething. Tomorrow I’ll disprove it, he thought. Tomorrow I’ll go to every household I know and determine their fluid source, and then we shall see.

***

### September 6th

Henry sat in front of his holocom, staring at it somewhat blankly. He needed to make a call, and yet he had no idea how to begin.

He had spent the past days with those who had fallen ill in Broad Street, using every interpersonal skill he had to elicit trust and information. Then he had visited those in the surrounding Streets. Then he had retraced his steps, and interviewed all those who had remained healthy. With every interview his conclusions grew more certain and more baffling. 

He had interviewed an android mining team in Heddon Street, who had fallen ill as one, the only such case in Heddon Street - they had refueled in Broad Street on the evening of the 1st. A similar team based out of Broad Street were among the few in that Street with no symptoms whatsoever - they had refueled in Warwick, returning home only on September 3rd. 

Although every principle rebelled at the thought of blaming recycled fluids for the epidemic, Henry was forced to admit the preponderance of facts were weighted in favor of the theory proposed by Dr. John Snow. However, there remained one logistical concern which held him back from a wholehearted endorsement. 

In the course of his visits, he had frequently passed the primary location of the waste recycling system in Broad Street. It was somewhat unique in boasting a single centralized location for the deposit of all personal waste. As far as he could tell, it was well-kept, with no obvious signs of uncleanliness. He was reassured by many who lived nearby that in general they felt it had no negative effect on the health or safety of their location. Indeed, many who lived outside of Broad Street came to Broad Street specifically out of a preference for the products of their recycling system - Broad Street had a reputation for clean, pleasant smelling fluids, appealing to oil-drinkers and water-drinkers alike. Unfortunately so in this case, Henry thought with a shudder - he had that day visited a sufferer in Hampstead who was prostrated by the most vicious symptoms, only to learn that she had specifically sent to Broad Street out of a preference for its oils. 

But if the Broad Street recycling system was the source of the illness, why was it that even in Broad Street itself the number of new cases continued to decline? Most patients had felt the onset of symptoms between the 1st and the 3rd, with so few new cases on the 6th that Henry dared hope the epidemic was near its end. Had a flaw in the Broad Street waste recycling system fixed itself? Henry could not believe the recycling system could have failed immediately prior to the epidemic, yet successfully processed the vast quantities of noxious effluence added to the system since symptoms commenced.

Yet there it was. Something had happened in the Broad Street waste recycling system, and there was only one man who knew enough to identify what it could be. Harry touched his holocom screen.

The call connected; the “voice only” light blinked on.

“Dr. Snow?” Henry said hesitantly.

“Yes?” The voice from his holocom sounded the same as he remembered from the Board of Public Health hearing; husky and curiously flat.

“Sir, my name is Henry Whitehead, in Berwick Street. I attended your address to the Board of Health on the second of September, where you brought forth your theory of fluidborne contagion?” Henry couldn’t help the rise in his voice, though it made him sound far too hesitant. He needed Dr. Snow to treat him as an equal researcher, but after the last few days he found his confidence sorely lacking. 

“Yes,” said Dr. Snow again. Henry waited for him to continue, but it seemed that was to be all. 

Henry cleared his throat. “Well, sir, I must admit I found your theory to be unconvincing - I had myself spent the previous day in Broad Street with many struck by the epidemic, and had seen only improvement in those sufferers who increased their intake of fluids directly from that recycling system. After hearing your theory, I took it upon myself to interview those affected by the epidemic with particular attention to their fluid source on September 1st. I am the designated psychologist for this district, you see, so I am in frequent communication with most individuals - they know me and have been willing to share the particulars of their habits.”

Henry paused to regain control of his thoughts, absent any interjection from Dr. Snow. This was the difficult part. “After interviewing those affected directly by the illness, I found myself compelled to also circulate among those unaffected and ask the same questions regarding their fluid sources. I visited every household in Broad Street, and most in the surrounding Streets. The pattern I found was striking. Although it was to be expected that most of those individuals living in Broad Street took their water from that recycling system, the most extraordinary pattern - I cannot even tell you -” He stopped and took another breath. “In short, what I found was this: almost all those individuals struck with symptoms on September 1st recalled taking fluids from the Broad Street system on that day or the day immediately proceeding. None of the individuals without symptoms, in Broad Street or elsewhere, took fluids from the Broad Street system.”

“I am delighted to hear that,” said Dr. Snow, sounding anything but. 

“But I don’t understand it!” Henry burst out. “You said the symptoms were spread by dead nanites, but the most integral function of nanites is that they do not leave the body whole, and fragmented nanites can have no effect on the living body! This is impossible, Dr. Snow, this throws into question every element we rely on to enable the continued functioning of our mission and our lives!”

There was a pause. “You had better come over,” Dr. Snow said finally. “Tomorrow. My offices are in Sackville Street. I am performing ongoing nanite analysis.” He paused, then said, “I would be thankful for the opportunity to hear your opinion on my work, and gain further insight into your own research into this situation.” Without another word, he ended the call.

***

### September 7th

Henry parked his rover in Sackville Street well after midday. He had intended to arrive earlier but his presence had been requested by no fewer than six households, although thankfully all recovering to greater or lesser extent. As he sat patiently through decontamination, he let his mind dwell on what he knew of Dr. Snow so far. He had mentioned the man somewhat off-handedly to several individuals that day, and had been surprised at the reception - not only did everyone seem to know who he was, he was held in the deepest respect by all. He seemed to have visited almost as many of those stricken with illness as Henry had, and although he was widely acknowledged to have no bedside manner in the least, his medical recommendations seemed to be held in great esteem and were followed to the letter. When Henry had hesitantly brought up the subject, one old fellow had said, “Well, yes, sir, must admit some of his more outlandish theories can be a bit over the top. Generally speaking though, you find he is right in the end. After all, you know how that type can be!” He laughed, then sobered - probably due to the expression on Henry’s face - and hastily said, “Begging your pardon, sir. No offence meant.”

Henry said something conciliatory in the moment, of course, but he found himself growing angry again at the memory. The little jabs that drove a chasm between humans and androids were his greatest annoyance - possibly because they were also his greatest fear. With only one of the two life forms isolated, the other must surely fall. Humans and androids were interdependent upon one another, especially on an isolated planet such as this one. Where one could not pass, the other thrived; no mystery could withstand the force of their combined attention. 

Perhaps that was why he felt so drawn to Dr. Snow, Henry thought absently, just as the decontamination portal opened. He hurried down the hall, and immediately spotted Dr. Snow’s offices. The biometric scanner recognized him and admitted him immediately. “Here,” he heard Dr. Snow’s voice, and turned a corner to find himself in a large library, currently serving the purpose of an elaborate laboratory. Henry could admit to himself that he knew the purpose of very little there, except, of course, the nanoscope itself, vaguely recollected from primary school. This one was nothing like the simplistic equipment of Henry’s school days, however. It was at least twice as large, with various connecting apparati at every juncture. Tubes and wires crossed crossed the room, and Henry watched his step very carefully as he crossed to where Dr. Snow awaited him. 

“Dr. Snow, I am deeply grateful for your invitation,” he said, and stuck out his hand - then winced, recalling that many of Dr. Snow’s type preferred not to make physical contact with strangers. To his relief, however, Dr. Snow shook his hand firmly and without hesitation. 

“Indeed, it is I who am grateful,” Dr. Snow said, his quiet voice more confident and less abrupt in person. “Your work to track the habits of those individuals affected by the epidemic has far outstripped my own efforts, and I believe may be the most needed information for our ultimate conclusion.”

“I would be pleased to reach any conclusion at all!” Harry said. “So far, I must admit it seems unlikely to me. I am relieved to see a sharp decline in contagion - did you know, doctor, I have not seen a single new incident today? - but I am quite afraid that if there is no proof of the source, they may just as easily be another epidemic tomorrow.”

“Indeed,” said Dr. Snow, frowning. “In that case, you will be pleased to know that I am quite sure I am nearing my proof. Allow me another few hours with my nanoscope and I believe I will have something to show you.”

“That would be truly wonderful,” said Henry, not trying to hide his amazement. “Shall I leave you to it? I wouldn’t want to delay you.”

“Not at all,” said Dr. Snow. “I am sure it will not be long. And I do want to hear more about your interviews. Take a seat.” He gestured towards a nearby armchair. “And please, call me John.”

Henry sat, unaccountably pleased. There was a certain something about Dr. John Snow, in person - he was beginning to understand the respect the doctor inspired in his patients. “You must call me Henry as well,” he said. 

“Then, Henry,” said John, “Tell me everything.” And he looked directly into the nanoscope. 

“Well… I…” Henry found himself at a loss for words. 

“I am paying attention, you know,” John said softly, and suddenly Henry found it quite easy to speak. 

“I visit Broad Street quite frequently during the course of my work, you see. As I believe I told you, I am the district psychologist, so it is my responsibility to ensure all residents are mentally and emotionally healthy.”

“You help them process trauma, and so forth?”

“Not - well, occasionally.” Henry’s mouth twisted. “I don’t provide therapy, of course, but isolated as we are, someone has to help, and I am frequently the only one around with anything resembling training. No, I believe most of the people I visit see me as a friend, or at least a companion. I believe that is why I had the success I did in gaining full accounts of their daily movements and habits.”

“Do you enjoy your role?”

Henry froze for an instant. It was an unexpected question, and under other circumstances perhaps one he would refuse to answer. But knowing John’s eyes weren’t on him made him feel peculiarly free. “I volunteered for this mission, you know. I thought I could - I thought it could make a difference for someone with my background to join.”

John hummed softly, not taking his eyes off his nanoscope. “Stage II terraforming missions have unusually high rates of depression and anxiety among humans, while robots are thirty percent more likely to develop looping algorithms that hinder their overall processing time.” 

“It’s difficult for both our kinds,” Henry acknowledged. “Stressors abound, from the most basic adjustments to gravitational changes, to leaving behind familiar environments and loved ones, to… well, to unpredictable physical ailments. But I never expected… I don’t know what I can—”

John held up his hand abruptly, and Henry stopped talking. “Here,” John said. “Look at this.” 

He flipped on the holographic projector on the nanoscope, and Henry drew closer, fascinated. John had isolated several nanites, two of them live and whole, surrounded by multiple dead fragments. One of the live ones was a strange shape, however. Rather than the usual 5-limbed nanite shape, this one seemed to have an extra appendage connected to one side. As they watched, the nanite seemed to quiver, then fragmented into four distinct pieces… all in the same exact shape. Henry noticed, with a start, that the other dead fragments in the petri dish matched the shape as well. 

“Look,” John said, and pointed. One of the fragments was drifting towards the remaining whole nanite, and as they watched, bumped into it. Immediately the smaller piece attached itself to the whole, gaining the same six-armed shape as the nanite they had just watched break apart!

“Oh,” Henry breathed. 

“Yes,” said John, his voice warm and avid. “The particular fragment shape is able to connect to live nanites, consistently stressing them in such a way as to break them into the precise same fragment shape. It is a self-perpetuating system, Henry - the fragments are dead, and yet that does nothing to prevent them from replicating themselves. If only one enters a healthy system, then - well, then we may count ourselves lucky to have any healthy nanites remaining to us at all.”

“Enters the system - but that’s just it.” Henry grabbed John's arm and pulled him around. John’s eyes went wide, but Henry couldn’t stop, the words pouring out of him. “They couldn’t possibly! John, they couldn’t have come from recycled fluid. It was one thing I made sure to find out. The waste itself is separated by nanites, so of course dead nanites must be removed from the system first, as nanites cannot operate upon other nanites - or at least, so we thought.” He stopped in confusion. 

John paused a moment. “Then,” he said, imperturbable, “we must visit the Broad Street waste recycling system.”

***

### September 8th

Broad Street was one of the oldest habitats in the area, built during the original Stage I mission. Although its corridors were confusingly maze-like and it gave a disturbing impression of being likely to fall to pieces at any minute, it engendered a great deal of loyalty in its residents. Every inch of the place had been put together by hand, nothing pre-fab or duplicative. The centralized waste deposit system was a wonder of modern engineering, in its way - a public demonstration of the consequences of the most private of acts.

John surveyed the scene, watching as people entered and left the private stalls, greeted each other, promoted their events, and performed all the other activities individuals seemed to gravitate towards when given the option of a public square. The effects of the epidemic could hardly be seen, with no break in the crowds to indicate the dozens who had been bed-bound only a few days prior. One enterprising fellow had even set up a market stand, and seemed to be doing a brisk trade in wet wipes, disinfectant, and extra-soft papers. Henry tried not to twitch impatiently as he waited for John to speak.

“No,” John said finally, “our answer will not be here. You are quite correct that if this had been the source of the contagion, the emissions from the ill would have caused a rise in new cases, rather than the decline we have seen.” He turned to Harry decisively. “Is this the only depository location in the Street?”

Harry blinked, caught by surprise. “Yes, of course it - wait.” He frowned. “There might be… although I don’t think… well.” He looked at John appraisingly, then laughed. “Yes, I think I shall introduce you to Sarah Lewis.”

***

“Ms. Lewis, may I present Dr. John Snow? He is doing some research on the causes of the recent cholera outbreak. Dr. Snow, this is Ms. Sarah Lewis, one of the original Stage I mission members.”

The lady upon whose doorstep they stood appeared severely unimpressed. She looked John up and down, her gaze sharp enough that even the usually phlegmatic doctor briefly shifted from foot to foot. The silence lasted one uncomfortable second too long, until she cleared her throat and said, “I suppose you’d better come in.” She stood back and allowed them to enter what was possibly Henry’s favorite apartment in the district.

The floor, chairs and tables were neat as a pin - any surface could serve as a hygienic spot for a meal or laboratory experiment on a moment’s notice. But the walls, the walls were crammed with pictures, articles, holos, samples, anything imaginable relating to the art and science of planet terreformation. Henry drifted towards them helplessly, as he always did, and knew Sarah would be starting to laugh at him behind his back, as she always did. He heard John begin to explain his theory of fluidborne contagion, and to question her regarding her habits and experience in the past week. He only half paid attention until he heard her say, “Well, yes, now that you mention it, I did have a bit of trouble. August 31st, I believe it was.”

August 31st! Henry turned around. That would have been the exact day of an initial case, if there was an initial case. “But not the cholera, I hope?” he said, forcing himself to be calm.

“Oh, no, certainly not. No, some minor stomach trouble. The bowels, you know,” she said, turning to John, who managed a creditably grave, “Indeed I do.”

“This may sound strange, Ms. Lewis,” Henry said, “but… do I recall correctly there is a private waste deposit area in your apartment? Not to use myself, I mean,” he added hastily, “but there is a theory, you see, we are following a theory.”

Sarah’s single raised eyebrow showed what she thought of his theory, but she led them back through the apartment and opened a small door. The three of them crowded around. Inside was an old-fashioned depository shaped to accommodate humans, complete with a manual flushing system. Henry barely held back a shudder - how far they had come from those old primitive days!

“Well,” John said with some satisfaction, “This indeed could have been the source. A single nanite, fragmented in precisely the wrong way and then passed into the recycling system, could easily have multiplied enough to cause the devastation we have seen.”

“No, the same problem remains,” Henry said in frustration. “If there was such a fragmented nanite, why did the recycling system not filter it out? We must find a way to look directly into the system itself.”

“It’s here,” Sarah said, and kicked the wall demonstratively.

They both stared at her. 

“On the other side of the wall,” she said helpfully. “Do you boys think I don’t know this station backwards and forward with my eyes closed? I assembled that nanite scraper with my own hands - it’s behind this wall here.”

“We must look at it,” Henry said urgently.

John nodded. “Perhaps a laparoscopic device? Or maybe a—”

“A screwdriver,” Sarah said firmly. She pulled one out of her pocket and proceeded to remove the wall panel.

Henry was forced to admit he understood nothing about the circuits and tubes thus revealed, and was content to stand back while John and Sarah poked and prodded. 

Finally John looked up. “It is precisely as we could have expected. This break in the circuit here has allowed waste from this depository, and only this depository, to enter the waste recycling system precisely after the nanite fragment cleansing process is complete. Every element of Broad Street waste is recycled perfectly… except dead nanites.” He stood, brushing off the knees of his trousers.

“But… how do we fix it?” Henry said. “We cannot shut down the entire recycling system while we determine a permanent solution.”

They stood in helpless silence for a moment. Then, John reached out to the depository flushing device, and removed the handle.

*** 

They walked back towards the decontamination bay together, in companionable silence. Henry found himself caught by the cheerful swirl of life around them - children running through the corridors, neighbors greeting one another. He found himself remembering the eerie quiet of Broad Street on September 1st, his first clue to the enormity of what was about to happen. And now the epidemic had simply vanished, for all that could be seen of its effects. 

Henry glanced towards John and found him frowning down at his feet, unnoticing of the bustle around them. He glanced up readily enough, however, seeming to understand the source of the curiosity in Henry’s quick look.

“I was only thinking,” he said diffidently, “of how it seems the results of this epidemic have changed… oh, how we must think of the health of communities in these Streets. How humans and androids are physically interdependent upon each other. Everything.”

Henry almost laughed out loud. In response to John’s raised eyebrows, he said, “It is only that I was thinking the opposite.” He gestured to the passers-by. “They go on as if it had never been.”

John blinked, then smiled in return. “I believe, Henry, this can only show that humans and androids are not only physically interdependent, but that we must depend upon each other mentally as well.” He bowed slightly. “My theories would have remained merely hypotheses, without your persistence in both finding their flaws and remedying them with proof.”

Henry felt his own smile grow wider at the unexpected compliment. “Well! I thank you very much. I interact frequently with both humans and androids, you know, during the duties of my position, but I must admit that you are the first human with whom I have worked this closely. I can only say that if other partnerships like ours can produce similar results, we may see some great advancements made during our lifetimes.”

“Indeed,” John said solemnly, and together they walked through the decontamination portal.

**Author's Note:**

> So, so much gratitude to CJ, Jake, Jamaica, and Zack - I am extremely lucky to have friends who not only didn’t run screaming when I followed up “1850s London cholera epidemic RPF” with “I can’t decide between robot cholera or cholera in space”, but offered ongoing and enthusiastic support. Y’all are the best. I messed with the timeline, it’s for handwavy plot drama purposes, if you’re a purist you have my deepest apologies. If anyone wants to know more about the 1850s London cholera epidemic and the real life Holmes and Watson team of Snow and Whitehead, which you definitely should, "The Ghost Map" is a pretty good book but also Whitehead’s own retelling of the story is [here](https://books.google.com/books?id=iSiFb2ANrG8C&pg=PA113&fbclid=IwAR0FqLqdj_oE7xhCM1fDjXNGrviTBHvkJjdGjxHE9OQXAbazRw8x-vNaepA#v=onepage&q&f=false) for free and is super dramatic and also includes a whole bunch of poop euphemisms, including the brilliant line, “other abominations, unmolested by water, which I forbear to recite.”


End file.
